I am using Opensuse 64 bit,everytime I need to open the platform it downloads.
it bothers me.
jForex platform ALWAYS downloads every time You start it. In doesn't depend on the operating system that You use.
For me, on Linux Mint 13, right-click & drop-down-menus weren't working on icedtea; haven't tried with oracle java on it though.
Regarding your concern about platform downloading, neither Oracle or IcedTea Linux JVMs contribute to this behaviour, therefore the question is better restated "Why does the JForex platform always download upon starting?".